Case 1
- Electric charge
- 0.001C
- Velocity perpendicular to the field
- 100m/s
- Magnetic field strength
- 0.2T
0.020000N
Open with these valuesLorentz Force Calculator
0.020000N
Result: 0.020000 NThe magnetic force on a moving charge is charge times velocity times field strength. It assumes the charge moves perpendicular to the field, where the force is largest; along the field lines it is zero. This is the magnetic half of the Lorentz force — add qE separately if an electric field is present.
The numbers at a glance
Held fixed: Electric charge 0.001000 C, Velocity perpendicular to the field 100.000 m/s.
| Magnetic field strength (T) | Result (N) |
|---|---|
| 0.0000 | 0.000000 |
| 0.0500 | 0.005000 |
| 0.1000 | 0.010000 |
| 0.1500 | 0.015000 |
| 0.2000Your value | 0.020000 |
| 0.2500 | 0.025000 |
| 0.3000 | 0.030000 |
| 0.3500 | 0.035000 |
| 0.4000 | 0.040000 |
Worked examples
Case 2
- Electric charge
- 2C
- Velocity perpendicular to the field
- 3m/s
- Magnetic field strength
- 4T
24.000000N
Open with these valuesCase 3
- Electric charge
- 1.6e-19C
- Velocity perpendicular to the field
- 1000000m/s
- Magnetic field strength
- 0.5T
0.000000N
Open with these valuesHow it's calculated
F = q × v × B
- StepEnter the charge in coulombs — an electron carries 1.6e-19 C.
- StepEnter how fast it moves across the field, in metres per second.
- StepEnter the flux density in tesla.
- ResultRead the force in newtons; it acts sideways, never along the motion.
Reference table
| Charge, velocity, field | Setting | Force (N) |
|---|---|---|
| 0.001, 100, 0.2 | Charged dust grain in a weak field | 0.02 |
| 0.002, 5000, 0.05 | Fast ion beam, weak field | 0.5 |
| 1, 1, 1 | One coulomb, one metre per second, one tesla | 1 |
| 0.5, 200, 0.1 | Half a coulomb across a small magnet | 10 |
| 2, 3, 4 | Textbook whole numbers | 24 |
Questions
How do I calculate the Lorentz force?
Multiply the charge by the velocity and by the magnetic field strength: F = q × v × B, valid when the velocity is perpendicular to the field. Use coulombs, metres per second and tesla to get the force in newtons. An electron at 1,000,000 m/s in a 0.5 T field feels 8e-14 N.
What is the Lorentz force?
It is the force a magnetic field exerts on a moving electric charge. It makes charged particles curve in a field, drives electric motors and bends beams in particle accelerators. The magnetic part is measured in newtons.
Why must the velocity be perpendicular to the field?
The full magnetic force is F = q × v × B × sin θ, where θ is the angle between velocity and field. It is largest when the motion is perpendicular and zero when the charge travels along the field lines. This calculator assumes perpendicular motion and therefore reports the maximum.
Does this include the electric force?
No. The complete Lorentz force is F = q(E + v × B), combining an electric term qE and a magnetic term qv × B, and only the magnetic part is computed here. If an electric field is also present, add qE separately.
Why does the result show as zero for an electron?
Elementary charges are around 1.6e-19 C, so the forces land near 1e-14 N — far below the six decimal places this page can display. The calculation itself is exact; only the readout runs out of digits.
Sources and last check
Information, not professional advice.